1. Field of the invention:
This invention relates to a semiconductor light-emitting apparatus that has a low ripple rate on the optical intensity of the near-field pattern.
2. Description of the prior art:
Semiconductor laser devices that are useful as light sources for optical discs, laser printers, optical communication systems, etc., must produce high output power. For this purpose, semiconductor laser array devices, in which a plurality of waveguides are disposed in a parallel manner to achieve an optical phase-coupling between the adjacent waveguides, have been studied by, for example, the inventors of this invention, Applied Physics Letters, Vol. 47(4) PP. 341-343 (1985).
However, the studies of semiconductor laser array devices have been focused on the production of high output power and/or the attainment of oscillation in a transverse mode with a 0.degree. -phase shift, but they have not been focused on the uniformity of the optical intensity of their near-field patterns. For example, the inventors of this invention have experimentally obtained the near-field pattern shown in FIG. 5 by the use of a loss-guided semiconductor laser array device with three waveguides (Journal of Applied Physics, Vol. 58(7), PP. 2783-2785 (1985)). This array device produced high output power of 100 mW or more, but it can be seen from FIG. 5 that the ripple rate of the optical intensity of the near-field pattern is as high as 100%. That is, the optical intensity of the near-field pattern lacks uniformity.
The above-mentioned array device having a high ripple rate of the optical intensity of the near-field pattern is not applicable to optical systems in which the near-field pattern of the array device is utilized.